From 0e2b5eb41fc6820a80428de4a73ede6f47d74cf0 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Fri, 11 Jan 2019 21:16:31 +0100 Subject: [PATCH 146/347] rtmutex/rwlock: preserve state like a sleeping lock Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.tar.xz The rwlock is spinning while acquiring a lock. Therefore it must become a sleeping lock on RT and preserve its task state while sleeping and waiting for the lock to become available. Reported-by: Joe Korty Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior --- kernel/locking/rwlock-rt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/rwlock-rt.c b/kernel/locking/rwlock-rt.c index aebb7ce25bc6..8f90afe111ce 100644 --- a/kernel/locking/rwlock-rt.c +++ b/kernel/locking/rwlock-rt.c @@ -128,7 +128,7 @@ void __sched __read_rt_lock(struct rt_rw_lock *lock) * That would put Reader1 behind the writer waiting on * Reader2 to call read_unlock() which might be unbound. */ - rt_mutex_init_waiter(&waiter, false); + rt_mutex_init_waiter(&waiter, true); rt_spin_lock_slowlock_locked(m, &waiter, flags); /* * The slowlock() above is guaranteed to return with the rtmutex is -- 2.36.1